Chteinberg Emil, Wetzels Suzan, Gerritsen Wouter, Temmerman Lieve, van den Oord Joost, Biessen Erik, Kurz Anna Kordelia, Winnepenninckx Véronique, Zenke Martin, Speel Ernst-Jan, Zur Hausen Axel
Department of Pathology, GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Maastricht, Limburg, The Netherlands.
Experimental Vascular Pathology, Department of Pathology, Cardiovascular Research Institute Maastricht, Maastricht University, Maastricht, Limburg, The Netherlands.
Ther Adv Med Oncol. 2020 Dec 14;12:1758835920975621. doi: 10.1177/1758835920975621. eCollection 2020.
Merkel cell carcinoma (MCC) is a highly malignant skin cancer. Despite major treatment improvements during the last decade, up to 50% of patients do not respond to therapy or develop recurrent disease. For these patients, alternative treatment options are urgently needed. Here, we assessed the efficacy of the combination of the BCL-2 inhibitor Navitoclax and the PI3K p110α inhibitor Alpelisib in MCC cell lines.
The expression of BCL-2 was assessed by immunohistochemistry in MCC and MCC cell lines. Treatment with Navitoclax and Alpelisib alone and in combination was performed on four MCC cell lines. The decrease of cell viability during treatment was assessed by XTT assay and visualized for the combinations by 3D combinatorial index plotting. The increase of apoptotic cells was determined by cleaved PARP Western blotting and Annexin V staining.
Some 94% of MCCs and all three MCPyV-positive cell lines showed BCL-2 expression. Navitoclax monotreatment was shown to be highly effective when treating BCL-2-positive cell lines (IC-values ranging from 96.0 to 323.0 nM). The combination of Alpelisib and Navitoclax resulted in even stronger synergistic and prolonged inhibitions of MCC cell viability through apoptosis up to 4 days.
Our results show that the anti-apoptotic BCL-2 is frequently expressed in MCC and MCC cell lines. Inhibition of BCL-2 by Navitoclax in combination with Alpelisib revealed a strong synergy and prolonged inhibition of MCC cell viability and induction of apoptosis. The combination of Navitoclax and Alpelisib is a novel potential treatment option for MCC patients.
默克尔细胞癌（MCC）是一种高度恶性的皮肤癌。尽管在过去十年中治疗有了重大改进，但仍有高达50%的患者对治疗无反应或出现复发性疾病。对于这些患者，迫切需要替代治疗方案。在此，我们评估了BCL-2抑制剂Navitoclax和PI3K p110α抑制剂Alpelisib联合使用对MCC细胞系的疗效。
通过免疫组织化学评估MCC和MCC细胞系中BCL-2的表达。对四种MCC细胞系单独及联合使用Navitoclax和Alpelisib进行处理。通过XTT法评估处理过程中细胞活力的降低，并通过3D组合指数绘图对联合用药情况进行可视化。通过裂解的PARP蛋白免疫印迹和膜联蛋白V染色确定凋亡细胞的增加。
约94%的MCC和所有三种MCPyV阳性细胞系均显示BCL-2表达。当处理BCL-2阳性细胞系时，Navitoclax单药治疗显示出高效性（IC值范围为96.0至323.0 nM）。Alpelisib和Navitoclax联合使用通过诱导凋亡对MCC细胞活力产生更强的协同和持久抑制作用，长达4天。
我们的结果表明，抗凋亡蛋白BCL-2在MCC和MCC细胞系中频繁表达。Navitoclax与Alpelisib联合抑制BCL-2显示出对MCC细胞活力的强烈协同和持久抑制作用以及凋亡诱导作用。Navitoclax和Alpelisib联合使用是MCC患者一种新的潜在治疗选择。
